Applied Mechanics and Materials Vols. 465-466

Abstract: Aluminum silicon (Al/Si) alloy, a metal matrix composite (MMC), is widely used in various industrial sectors, such as transportation, domestic equipment, aerospace, military, and construction. Al/Si alloy is a matrix composite reinforced with aluminum nitride (AlN) particle and transformed into a new-generation material for automotive and aerospace applications. AlN material is an advanced material characterized by light weight, high strength, and high hardness and stiffness, which makes it suitable for various future applications. However, its high ceramic particle reinforcement and the irregular nature of these particles along the matrix material make it a low density material. This low density is the main cause of problems during machining of this material. This paper studies tool wear in milling AlSi/AlN metal matrix composite by using an uncoated carbide cutting tool. The volume of AlN reinforced particle was 10%. The milling process was carried out under dry cutting conditions. The uncoated carbide insert parameters used were the following: cutting speed of 230 m/min to 370 m/min, feed rate of 0.4, 0.6, and 0.8 mm/tooth, and a corresponding depth of cut (DOC) of 0.3, 0.4, and 0.5 mm, respectively. Sometech SV-35 video microscope system was used for tool wear measurements. Results revealed that tool wear increases at 230 m/min cutting speed, 0.4 mm/tooth feed rate, and 0.3 mm depth of cut. The medium cutting speed, specifically the 300 m/min cutting speed, 0.4 mm/tooth feed rate, and 0.5 mm DOC, is the optimum condition for a longer tool life (82.94 min) and is ideal for cutting AlSi/AlN MMCs.

Abstract: The effect of eco-degradant PD 04 as additive on the thermal properties of recycled polyethylene (RPE)/chitosan biopolymer was investigated. The different scanning calorimetric (DSC) was used to investigate the thermal properties of composites at various 0, 20 and 40 php. The DSC result shows the presence of eco-degradant reduces the melting temperature processing and increase crystallinity of the composites.

Abstract: As-received samples of an austenitic stainless steel AISI 304 type was welded by Gas metal arc welding (GMAW) robotic operation process using ER308L-Si filler metal wire. Two different atmospheres were used: 68% Argon plus 32% CO₂, and 100% Argon. The aim of this study is investigates the influence of quenching heat treatment on the mechanical and microstructure properties of AISI 304 type which welded by GMAW under different shielding gas compositions. The fractured surfaces of the tensile test specimens examined using scanning electron microscopy (S.E.M). The results showed that the welding using shielding gas of 68% Argon plus 32% CO₂ stronger than 100% Argon. After performed quenching heat treatment process, both specimens experienced a slight decreased in hardness.

Abstract: Metal foams are well-known as engineered materials with unique combination of physical and mechanical properties, yielding an attractive material for use in the aerospace industry, automotive and medical industry. In this study the method that been used to produce SS316L foam is slurry method. Slurry of stainless steel is prepared by mixing binder material such as methyl cellulose (CMC), polyethylene glycol (PEG) and distilled water by using ball milling machine. Then, the sample is sintered at different temperatures which are 1300°C, 1350°C and 1400°C. The value of porosity and density of SS316L foam are collected utilizing Archimedes method. As the result, the porosity percentage found in the range of 4.77 % to 59.80% meanwhile density value ranging from 0.402g/cm3 to 0.952g/cm3. The highest value of porosity is 59.80% at 1300°C for 40wt% SS316L, while, the highest value of density is 0.952g/cm³ at 1350°C for 60wt% SS316L. These results was followed the theory of porosity and density which are the value of porosity is inversely proportional to the density.

Abstract: Yttrium oxide nanopowder has been successfully synthesized by a modified transient morphology. In the first step, a foamy structure was produced by combustion synthesis using yttrium nitrate and glycine. This was followed by the addition of sulfate ions and calcination at 1100 °C for 4 h. The sulfated powders were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM). The XRD pattern shows Y₂O₃ single phase after calcination. The TEM images confirm the nanometric size of the particles in the range of 40-100nm.

Abstract: Silica sand nanoparticles are widely used as filler, coating and reinforcer to increase materials strength and durability. The objective of the research is to design a new technique of converting Tronoh silica sand to silica sand nanoparticles by using ingenious combination of milling process and heating mechanism. Raw Tronoh silica sand was milled for 10 hours with heating process after every 2 hours of milling and the results are analyzed using particle size analyzer. Particles size of less than 100 nm has been repeatedly achieved in this research. Findings from this research provide a simple and low cost alternative method of producing silica sand nanoparticles.

Abstract: Solid-state direct conversion method of recycled aluminium 6061 alloy to produce metal-metal composites was studied by using collected recycle chip. Different volume percent of stannum (Sn) matrix was studied to attempt the tensile strength and surface integrity of the aluminium composites product. Constant pressure was used to implement the cold forging process with constant sintering temperature. Single size of chip had been used which 2 mm length as suggested. The optimum result of yield strength and ultimate tensile strength is 3 Pa and 8.3 Pa for 20 vol% of Sn composition. Analysis shows that composites beyond 20 vol% Sn resulted in the tensile strength decreased.

Abstract: Injection moulding is one of the most efficient processes in mass production that can easily attain up to complex geometry product within a very short cycle time. To choose a suitable setting of parameter was very crucial, in controlling the quality of product with regard to their function. The main propose of this research is to optimize the injection moulding parameter for controlling the shrinkage and warpage of thermoplastics sample through practical injection moulding. The additional study for this project is to investigate the effect of nanoclay contents towards the parameter setting. In this experiment, the selected parameters were packing pressure; melt temperature, screw speed and filling time. The material that was selected for this project was a mixture of polypropylene and nanoclay with the addition of polypropylene-grafted-maleic anhydride as the compatibilizer. Three formulations were chosen, which was 0 wt%, 3 wt% and 5 wt% of Nanoclay. Each formulation was added with 15 wt% of compatibilizer. The experiment design for this project shall adopt the L₉4³ Orthogonal Array of Taguchi Method. By using the Signal to Noise Ratio responses, the optimum parameter for each formulation has been obtained. The findings of this experiment shall be useful for future manufacturing process in order to control shrinkage and warpage specifically for products made from polypropylene-nanoclay.

Abstract: The current study is presented into the investigation of the application of ultrasonic vibration on the lower punch during compaction process of powder metallurgy material. The lower punch is specifically designed of ultrasonic horn which has been tuned at frequency of 20 kHz and vibrates in longitudinal mode. Finite Element modeling was used to assist the design process of the lower punch or horn. The horn was fabricated using high grade aluminium alloy and mounted onto the ultrasonic system test rig and subsequently tested prior the experimental process begins. Various static and ultrasonic compaction procedures have been carried out to confirm the capability of the tool to operate. The compaction force was reduced significantly at the onset of ultrasonic vibration applied compared to without ultrasonic.

Abstract: In this paper, the development of rehabilitation device for patients who encounter walking weakness due to post-stroke effect is presented. The kinematic analysis was carried out in the initial stage of development in order to have an efficient mechanism. As guide to design the device, the walking motion of healthy physical subject for speed of 1 km/h was used and subsequently a mechanism was designed to create similar walking motion. The device functions to inculcate the movement of thigh and calf through appropriate rotation of hip and knee. A single actuator of direct current (DC) motor is used to actuate the rotation of the hip and the knee joints mechanism. The kinematic analysis of constructed device has been performed and the results conformed the functionality of the suggested mechanism. The fabricated prototype proves the combination of DC motor and cam mechanism can actuated the movement of hip and knee joint simultaneously and subsequently reduced the power consumption.